Last night's Person of Interest was a fun, fast-paced number of the week episode. But it also hinted that we might have a new kind of bad guy on the horizon who is obsessed with Finch the way the Joker is with Batman. Spoilers ahead.

Let's face it — this episode was basically a much-deserved love letter to first responders and the people who staff 911 call centers. Our number is a 911 dispatcher with nerves of steel, keeps her cool even when a 911 caller is in a car that's sinking beneath the water. She always knows what to say, and we get the feeling she's saved a ton of lives with her quick thinking.

Finch has taken a gig with 911 to keep watch on her, which also gives the show a chance to do some "as you know Bob" infodumping of 911 fun facts. For example: Did you know that a huge percentage of calls to 911 are butt calls from mobile phones? Did you realize that 911 calls are all archived in a vast database because they are so frequently used as evidence in court cases? Also, did you know that it's super easy to steal a sysadmin's key fob full of passwords because he'll probably leave it out on his desk? Oops, that last one probably isn't true, except if you're trying to motor your plot along.

While the gang cases the 911 call center, Fusco is enjoying his new celebrity status at work. He's the dude who brought down HR, so now everybody wants his advice on their cases. After some grousing, he decides to help a younger detective with a murder case. Which just happens to be related to this week's number.

A rich couple has murdered the husband's girlfriend for rich people reasons, and they've hired some professionals to clean up the mess they made. Namely, the woman called 911 before they killed her, and the police could use that call as evidence. But our pros have other plans — they kidnap an innocent kid, and tell our 911 operator that they'll kill him if she doesn't delete all the 911 calls made on the day of the murder. Many shenanigans are involved in this discovery, of course, including Reese punching out an entire bar full of pro assassins and kidnappers and Shaw shooting shit up with OCD precision.

There are two great takeaways, though.

One: Finch points out that the 911 call center is sort of like a version of the Machine, except that the danger has unfolded too quickly for the Machine to catch them in time. So basically the Machine could never completely eliminate crime or danger — we'd always need humans like our number of the week, answering phones for 911 and dispatching first responders.

Two: After the bombs are defused and Fusco and his possible new partner have caught the rich people being bloodthirsty killers, we are left wonder who the hell it was who masterminded the whole kidnapping thing to coerce the 911 operator to delete those calls. It's a guy who has a lot of technical expertise, and who is able to hack into closed juvenile records on the number — he knows her weakness is saving kids, because she lost a kid she was babysitting when she was a teenager.

Who is this criminal mastermind? All we know, as the episode ends, is that he's done the whole job remotely — and now he has Finch's number. He contacts Finch and basically says he's fascinated by Finch, and one mastermind to another, he's going to bring Finch down. It's sort of a Moriarty thing, except we don't get the sense they ever knew each other. Or maybe they did? Because Finch does a very uncharacteristic thing. Instead of telling the Machine Gang he was threatened, he just throws away the phone the Moriarty used and tells everybody that he said "nothing of consequence."

Um, hello? Moriarty is threatening you, and has demonstrated an ability to blow up buildings — that seems consequential. Shouldn't the gang know about it? Finch, what are you hiding?